Krofta engineering limited, india was started in 1983 with technical collaboration with krofta technologies corporation, usa. Krofta is the world leader in dissolved air floatation clarifiers [ daf] and the technology was developed and patented worldwide by its founder dr. Milos krofta.
The krofta supracell has a distinct edge over other systems when the sludge or water is recycled to the process and where the type of waste water varies. For pulp and paper industry the small volume and short retention time are extremely important, where the supracell is used as a save-all and in the de-inking process.
Working principle
Air is dissolved under pressure in the liquid, which is then released to atmospheric pressure in the floatation cell. As the microscopic air bubbles come out of solution, they attach to the suspended solids in the liquid, causing them to float to the surface forming a thick sludge. A special skimmer removes the sludge with the help of patented `krofta` spiral scoop and pours it into the stationary centre section from where it is discharged by gravity for either recycling or disposal.
Advantages
* specific clarification capacity - very high [160 - 220 lmp / sq. Mt]
* purchase cost - lower than other systems of comparable performance
* installation cost - low. Heavy supports not needed. Minimal load factor
* mobility - easy, relocation is easily accomplished.
* space requirement - minimal. The equipment is stackable one atop another and over existing chests
* cleaning - easy. Bottom is self-cleaning
* clarity - high. 20-30 ppm of filterable solids
* sludge consistency - thicker [2-3%] demands less area for sludge beds.
